First depends on how big of trading capital you are looking for.
Second, With a min of $5000-$10000 initial capital in a trading firm account, you should be able to borrow margin and have enough trading capital for you to start small....To me, $25000-$50000 is already a good enough account size range to make a living with....
So, ask around... guess if the money you are looking for is small, it is not hard to get. You can get a personal loan from bank or a loan company if your credit rating is good. But make sure the interest is reasonable.
But why don't you borrow from your own business ( make sure you have a payback schedule) instead of paying high interest to a third party?